STABILITY OF AN INHOMOGENOUS PLASMA IN A MAGNETIC FIELD

Journal Article · Mon Jan 01 04:00:00 EST 1962 · Nuclear Fusion, Suppl.

OSTI ID:4808731

Lehnert, B

The stability of a plasma confined by a magnetic field is discussed in terms of particle orbits, in a theory applicable to a plasma separated from vacuum by a sharp boundary which is rippled by a sinusoidal perturbation. An earlier theory is reconsidered and extended to include the effects of a continuous density distribution. The gradient drift in an inhomogeneous magnetic field is deduced from the macroscopic theory. Account is also taken of drift motions along the boundary, which give rise to displacements comparable to and exceeding the wavelength of the perturbation. For small wavelengths the plasma is found to be stable against small flute'' deformations, not only for a magnetic field convex towards the plasma but also for a field concave towards the plasma. This latter situation occurs when the field gradient is strong enough and the density distribution is not very steep. For larger wavelengths steadily growing oscillations occur, but the growth rate is reduced considerably below that given by the earlier theory. Similar conclusions apply to the problem of gravitation instability. The result provides a possible explanation of the observed stability of the Van Allen radiation belts and of the absence of rapidly growing disturbances in experiments with magnetic mirrors and rotating plasma devices. (auth)

• Research Organization: Royal Inst. of Tech., Stockholm
• NSA Number: NSA-16-023223
• OSTI ID: 4808731
• Journal Information: Nuclear Fusion, Suppl., Journal Name: Nuclear Fusion, Suppl.
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CHARGED PARTICLES
CONFIGURATION
CONFINEMENT
DEFORMATION
DENSITY
DISTRIBUTION
DISTURBANCES
FLUTE INSTABILITY
FREQUENCY
GRAVITATION
MAGNETIC FIELDS
MAGNETIC MIRRORS
MOTION
ORBITS
OSCILLATIONS
PHYSICS
PLASMA
RADIATION BELTS
ROTATION
STABILITY
SURFACES
THERMONUCLEAR DEVICES
VACUUM